In 2001 the Federal Communications Commission (FCC) allocated a 75 MHz Radio Frequency (RF) spectrum to support Dedicated Short Range Communications (DSRC). DSRC is an IEEE standardized protocol that provides national interoperability for wireless communications to and from vehicles. DSRC also includes broadband connectivity with the Internet. Thus, development for the infrastructure needed to support wireless inter-vehicle communications has been in place for several years.
Further, as is well known, almost all vehicles manufactured since the 1980s have contained one or more microprocessors connected by a communications bus. These microprocessors can communicate with each other and can also provide output to, and accept input from, external sources. Various vehicle components and systems, such as the engine, brakes, transmission, emissions control system, and the like in land vehicles may have associated microprocessors for reporting on and/or controlling the component or system. For example, most automobiles and trucks manufactured today contain microprocessors communicating on a bus using CAN (controller area network) communications, as is well known.
Although information has been used to improve efficiency of a single vehicle, information has not been used to improve driving patterns and routes for an entire transportation system. Existing systems do not warn vehicles directly of hazards on the road, such as ice, snow, rain, oil, etc. Further, vehicles do not warn each other of known hazards or road conditions. Systems also don't exist that provide wide area warnings to vehicles of environmental disasters such as chemical spills, fires, or floods. Further, although some short range systems exist to expedite emergency vehicles, such systems do not warn surrounding vehicles of the emergency vehicle's need to progress. Rather, existing signaling devices may transmit infrared signals to street lights attempting to coerce a green light for the emergency vehicle, but disadvantageously fail to communicate directly with vehicles in an emergency vehicle's path.
Further, present communications systems are inefficient because they do not limit messages to vehicles within defined regions of interest, but rather allow such messages to be transmitted even to vehicles and other receivers for which the message is of no value. That is, present systems simply respond when they transmit and receive a message, rather than making a determination based upon the relative positions and/or directions of a message sender and a message receiver. A system that transmitted warning and other messages to vehicles for which such messages would be of value—and only to such vehicles—would thus present significant advantages over present systems.
Accordingly, a system is desired for cooperative communication between vehicles or land-base stations to facilitate a safe and efficient transportation system. Such a system would advantageously provide for hazard detection and warning, emergency vehicle prioritization, and directional messaging control, including providing for efficient long distance communication using intelligent repeaters.